1. Molecular Characterization of Carbonic Anhydrase Genes in Lotus japonicus and Their Potential Roles in Symbiotic Nitrogen Fixation.
- Author
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Wang L, Liang J, Zhou Y, Tian T, Zhang B, and Duanmu D
- Subjects
- Carbonic Anhydrases genetics, Lotus genetics, Lotus growth & development, Phenotype, Plant Proteins genetics, Root Nodules, Plant genetics, Root Nodules, Plant growth & development, Carbonic Anhydrases metabolism, Gene Expression Regulation, Plant, Lotus enzymology, Nitrogen Fixation, Plant Proteins metabolism, Root Nodules, Plant enzymology, Symbiosis
- Abstract
Carbonic anhydrase (CA) plays a vital role in photosynthetic tissues of higher plants, whereas its non-photosynthetic role in the symbiotic root nodule was rarely characterized. In this study, 13 CA genes were identified in the model legume Lotus japonicus by comparison with Arabidopsis CA genes. Using qPCR and promoter-reporter fusion methods, three previously identified nodule-enhanced CA genes ( Lj αCA2 , Lj αCA6 , and Lj βCA1 ) have been further characterized, which exhibit different spatiotemporal expression patterns during nodule development. Lj αCA2 was expressed in the central infection zone of the mature nodule, including both infected and uninfected cells. Lj , did not result in abnormal symbiotic phenotype compared with the wild-type plants, suggesting that LjβCA1 or LjαCA1/2 are not essential for the nitrogen fixation under normal symbiotic conditions. Nevertheless, the nodule-enhanced expression patterns and the diverse distributions in different types of cells imply their potential functions during root nodule symbiosis, such as CO αCA6 was restricted to the vascular bundle of the root and nodule. As for Lj βCA1 , it was expressed in most cell types of nodule primordia but only in peripheral cortical cells and uninfected cells of the mature nodule. Using CRISPR/Cas9 technology, the knockout of Lj βCA1 or both LjαCA2 and its homolog, LjαCA1 , did not result in abnormal symbiotic phenotype compared with the wild-type plants, suggesting that LjβCA1 or LjαCA1/2 are not essential for the nitrogen fixation under normal symbiotic conditions. Nevertheless, the nodule-enhanced expression patterns and the diverse distributions in different types of cells imply their potential functions during root nodule symbiosis, such as CO
2 fixation, N assimilation, and pH regulation, which await further investigations.- Published
- 2021
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